Wave meter



April 20 1926. 1,581,219

J. o. MAUBORGNE ET AL WAVE IETER Original Filed August `e. 1920(2353956. @Fm ifi/67 Patented Apr. 20, 1926.

UNITED STATES PATENT OFFICE.

JosErII o. MAUBORGNE, or CHICAGO, ILLINOIS,Y AND GUY HILL, orWASHINGTON, DISTRICT or COLUMBIA.

WAVE METER.

Original application filed August 6, 1920, Serial No. 401,746. Dividedand this application filed February This is a divisional application ofapplication relating to ivaveineters No. 401,7/l6.

Our invention-relates to the art of radio signaling having for itsdominant object the use of a resonance wave coil as the essentialelement of a Wavemeter. The resonance Wave coil, which We will designatehereafter simply as Wave coil, functions as a complete oscillatingsystem. p

The object of the present invention is to provide a more simple andaccurate means than those in present use for measuring the length ofelectric Waves and also for transmitting from the Wavemeter radiosignals of definite known frequencies for the purpose of calibratingother Wavemeters or radio receiving apparatus.

In its simplest form the Wave coil is made in the form of a long heliX,uniformly Wound with suitable insulating Wire closely spaced so that theinductance per unit length is relatively large. n

7e have found that it is desirable to Wind the coil on a materialhaving` high insulating properties such as micarta, orbal-:elitedielecto. Wre get, therefore, in a comparatively short coil,the equivalent condition of a long line in the matter of yWave-3'development. y

In the use of the Wavemeter described in this specification for thepurpose of transmitting` definite Wave lengths or frequencies, We makeuse of a wave coil of distributed inductance and capacity on which aWave development is produced by the transmitting source of thewavemeter, the Wavelength of the said Wave development depending solelyupon the electrical constants of the coil and the position of thepotential application to said coil, the wave coil by itself constitutingthe complete oscillatory system. The electromagnetic waves of theoutgoing signals are emitted from each element of the Wave coil, and Wehave here a condition Where the electrical constants of the coil, theinductance,v

Serial No. 616,748.

lar or the same Wave coil is employed having distributed inductance andcapacity of such magnitude as to insure Wave development along the coilfor the frequencies of the signals We desire to receive and measure.

The electro-magnetic Waves of the incoming signals act uniformly on eachelement of the Wave coil and We accordingly have a condition where theinductance, capacity, resistance of the coil, and the E. M. l?. inducedin it by the incoming signals are all of a distributed character makingit in a sense an ideal Wave conductor.

Asv a source of exciting rour Wavemeter for the purpose of transmittingsignals of a definite frequency, We may make use of any of the methodsdescribed in our pending application Serial No. 389,450 covering the useof the Wave coil'as a'transmitter. Likewise in using our wavemeter forthe measurement of received signals We can make use of the variousmethods of using the Wave coil as a receiver, described in our pendingapplication, Serial No. 383,?20.

As stated above, the fundamental principles underlying the use of theWave coil for the measurement of transmitted and received 'signals havebeen described at considerable length in our two pending applicationsreferred to above and therefore further explanation of these principlesis considered unnecessary herein.

Oue of the main advantages that we claim for a Wavemeter of thecharacter herein described consists in the fact that the apparatus formeasuring or determining the Wavelength consists of a single element,which is a coil preferably in the form of a solenoid, as previouslydescribed, and which does not constitute aclosed circuit. By the use ofsuch a Wave coil no condenser is required. lVith most existing forms ofwavemeters which are capable of transmitting signals of a definiteWavelength and With most forms of Wavemeters Which are used formeasuring ggg 1,5e1,21e

wavelengths ot received signals, the accuracy of the wavemeter dependsto a large degree upon the accuracy of the calibration ot the variableor fixed condensers used in such waveineters. lt a lined condenser beused in a wavemeter, a variable inductance has to be employed which alsois subject to lack ot perinanency, thereby destroying the value of thewaveineter for accurate measurements. ln. our device as described hereinonly one element, that is, the wave coil itself, is used to determinewavelength, and therefore, it this coil be accurately constructed, thereis only ene element that has to be kept in accurate adjustment andthereby the accuracy ot the wavemeter is greatly increased.

ln addition, as stated above, this wave coil is in no way altered or theinductance or other constants ot the wave coil varied in order tomeasure or generate different wave lengths; in other words, we do notind necessary to change the effective length ot the coil. ln addition tothe facts stated above, it is evident that increased accuracy can beobtained because in using the wave coil tor different wavelengths nochange whatsoever is made in the wave coil itself, and no part of thewave coil has to be altered, moved, or adjusted in any manner, theentire change of wavelength being made ly means of moving a suitableslider or sliders associated either electrostatically orelectro-magnetically er by direct connection with the wave coil.

In the use of the wave coil as a wavemeter, suitable calibration scalesare associated with the coil in order that wavelenoths may be readdirectly trom said coil, or trom a suitable scale ot equal parts placedthereon with reference to a set of curves furnished with the instrument.

ln connection with the use of the wave coil as a wavemeter we mayassociate it as a detecting instrument, any torni of a detector andreceiver known to the art. In its siniplest torni we may take a crystaldetector and shunt it with a pair et high resistance,

telephone receivers connecting one side et the detector by a suitablesingle lead to the slider on the wave coil. To use the wave coil as atransniitting wavemeter, we may employ a suit-able buzzer, actuated by abattery and connected to one side of the make and break oit' the buzzerby a single lead to said slider on said wave coil.

The use of our device as a. wavemeter also has one advantage over theordinary type of wavemeter because by employing a suitable ainpliiier inconnection with the wave coil, accurate calibration of distanttransmitting stations can be determined. Since the action ot' the wavecoil for determining the length ol' received signals depends entirelyupon the position of a single slider on the coil to which a single leadis attached, any desired degree of amplilication can be employed withouteffecting the calibration of the instrument in the slightest degree.

As stated above, in the use of this wave coil as a transmittingwavemeter, the length ot' the wave set up on the coil depends upon theposition of application of potential to the coil. By charging the pointot application of the energy source to dilferent positions along thecoil, moving the slider on the coil always in vthe saine direction .tromthe center, different wavelengths are set up on the coil tor eachposition ot the application point and these are entirely independent ofthe construction or constants of the lead and the associated circuitsdevised for supplying energy to the coil. `When the energy is impressedon the center of the wave coil, the shortest wavelength is obtained. isthe slider or point ot potential application is moved away from thecenter in either direction towards the ends ot the coil., the wavelengthgenerated is increased. The maxinuun wavelength is produced when theenergy application point is near either end oi' the coil.

An identical calibration applies when the wave coil used to measurereceived signals. in the specitications as given above, and in thetigures shown in this application, the wave coils are shown as coilsuniformly wound in the form oit a long hel'x. It is to be understood,however, that the invention is in no way limited to the use of a wavecoil ot this simple construction. It desired, in order to get anextremely long wavelength or a great range ot wavelengths in a givenspace, multiple layer coils may be employed. ln addition, the winding`of the coil may be banked on one halt, or closely wound in the torni ofa lump on one halt and distributed or wound with wider spacing on theother halt ot the helix in or'ler to obtain a very accurate measurementof a shorter range of wavelengths over a comparatively Along` space ot'coil. l l

Numerous other variations are evident, but it is considered unnecessaryto describe 'them as it is considered that they are all merelymodifications of the principle ot our invention which is to accuratelydetermine wavelengths by the use of a single calibrated coil used withassociated apparatus whicn does not require calibration. By the use oi5our device, however, it is never necessary, in tact it is undesirable,to connect the ivave coil to the antenna system or associated apparatusby any means whatsoever or anv transmitter or receiver, the 'frequencyoi wavelength of which is to be determined. Neither is it necessary toconnect said wave coil to earth for the'purpose of any measurements.

of using our invention can better be understood by reference to theaccompanying diagrammatic figures which show typical embodiments of theinvention and form part of this specification. In all of the figuresherewith the same symbols and nomenclature are used to designate thesame apparatus and further reference to various common symbols will notbe repeated except in cases where it is necessary to make clear thedifferences between the various figures.

In the accompanying drawings, Figure l is is a diagrammatic view of thesimplest form of the device as a practical wavemeter, embodying beth thetransmitting and receiving features;

Figure 2 shows a diagrammatic view of the wavemeter as the receiver,only, in which the vacuum tube detector or vacuum tube detector andamplifier are employed, as the detecting element; Y

Figure 3 is similar lto Figure 2 except that a different type of slideris used on the wave coil;

Figure t is similar to Figure 3 except that there is introduced aneutralizing lead;

Figure 5. shows a modification as to the transmitting side of thewavemeter of th-e device when used for generating different wavelengthsFigure G likewise shows in diagrammatic form another modification of thewave meter used as a transmitter.

Having more particular reference to the drawings and to Figure 1, Arepresents the wave coil consisting of a helix of suitably insulatedwire, preferably copper, closely wound in a single layer on aninsulating tube. We prefer to make the length of the helix greater thanits diameter. B indicates the slider making direct contact with the wavecoil and capable of being moved along the wave coil. a pointer Y whichmoves over a graduated scale W, showing directly the calibration on thecoil in wavelengths or frequencies.y

E represents the switch connected to B by a single lead.A This switch.as shown in the figure, can either connect B to the receiving apparatusor to the transmitting apparatus of the wavemeter. Vhen this switch isthrown to contact 3, the wavemeter is adapted for the measurement ofreceived signals. Contact 3 is connected to one side of a crystaldetector D, to the terminals of which detector are connected a pair oftelephone receivers T. When the switch E is thrown on contact 4, thewave meter can be used to transmit waves of predetermined length.Contact 4 is connected to X, 'one side of the make and break of thebuzzer Z as shown in the figure. The buzzer operates when the switch Fis closed on contact 5 thereby completing the circuit of battery G,through the coils ofthe buzzer.

In the succeeding figures certain modifi- B is provided withA cations ofthe wavemeter as a transmitter and as a receiver are shown The scale Wand pointer Y are not repeated-in the succeeding diagrams. n i

Figure 2 shows a modification of our wavemeter when used for themeasurement of received signals at a considerable distance from thetransmitter. By using vsuitable amplifier C, the connection shown inthis 'figure enables the direct measurement of received signals to beobtained at a great 4distance from the transmitter. This 'Figure 2 isidentical with Figure G of' our application Serial Number 383,720.figure A and B represent the coil and slid-er respectively similar tothose shown in Figure 1. In this case the lead from the slider to thereceiving device is indicated by the numeral l. The lead, in the case ofa vacuum tube detector, is always brought to the grid input terminal ofthe detector, or in the case of a multiple stage amplifier, to the inputterminal ofthe first stage of the amplifier. Telephone receivers T inthis diagram are plugged in ata suitable point in the circuit of theamplifier or vdetecter C. The operation of the wavemeter when employingconnections as shown in Figure 2 is identical with the use of thewavemeter asl a receiver, as described in our patent appli-v cationSerial Number 383,720. In 'other words, the device referredto in ourpatent application Serial Number 383,720 ust mentioned alreadyconstitutes awavem'eter Figure 3 shows a diagrammatic view sinulartoFigure 2 in all respects except that slider B makes electro-staticconnection with wave coil A instead Iof the direct connection made byslider B in Figure 2. This slider B may take any desired form such as anopen or closed cylinder or an open or. closed disc of metal. Figure 3 isidentical with Figure l of our patent application Serial Number 383,720.

vFigure 4; is a diagrammatic view similar to Figure 3 except thatl aneutralizing lead indicated on the figure by 2 is twisted with lead l ofFigure 3 so as to produce a twisted pair. One end of the neutralizinglead is attached to the filament, but the other end is left disconnectedas shown in the drawing. The advantage of using the twisted pair ofleads is that any radio energy which might be picked up by t-he leadfrom the .slider to the grid input terminal of the amplifier isneutralized by an equal amount of energy received by the filament lead.I-Ience no signal is produced in amplifier C due to the energy receivedby the leads. Under certain conditions this connection is ofconsiderable advantage. Figure of this specitication is identical withFigure 2 of our patent application Serial Number 383,720.

Figure 5 is a diagrammatic view showing a modification of thetransmitting arrange- In this en l ment .shown in Figure l. A representsthe Wave coil to which at point P is connected, by any onev of themethods described, a lead from a suitable source of undamped Wavepotential V, so designed as to produce at P on coil A a high potential.This ligure is identical with ligure 3 ot' our pending applicationSerial. Nun'iber 389,450, describing the use oli a Wave coil as atransmitter.

Figure G is a diagrannnatic vieiv showinganother modification of the useof the Wave coil as a transmitter. This ligure is similar to Figure lexcept that in place ot utilizing a buzzer as a source ot high potentialto actuate the Wave coil A, a simple induction coil with a spark gapacross its secondary terminals is employed. rl`his ligure is similar toFigure l oill our pending application Serial Number 389,450 descril'iingthe use of the wave coil as a transmitter. except that the interruptero't the induction coil is Shown in slight-ly di'li'erent form.

l/Vhile We have referred in this specitication particularly to the useof our device tor the purpose of measuring or generating radiofrequencies, it is to be understood Y that the Words radio frequenciesare intended to cover frequencies ot approximately 5000 or above whetheremployed for radio signaling or tor any other purpose and Where it mightbe desired to determine or measure the Wave lengths oie the 'trequeicies employed.

lt is also obvious, as We have stated above, that various changes andn'iodilications may be made in the Wave coil and its associatedapparatus herein shown and described Without departing from the spiritof our invention or the scope of the following claim.

Claim:

ln an apparatus for producingelectromagnetic energy ot predeterminedWave length, the combination o an open circuit and ungrounded resonanceWave coil having lined distributed inductance and capacity and beingcapable or having' developed thereon standing Waves et a Wide variety orfrequencies, the 'frequency ot the energy in. the wave coil beingdetermined solely by the electrical constants ot the coil and the pointof application of a high potential from a local untuned energy source,means lor varying the point oi application to said coil ot said highpotential, means for electrically connecting said pointot application tesaid high frequency sources and calibrating said Wave coil so that thepoint olf application et the high 'frequency source will detern ine thefrequency of the electromagnetic energy in the Wave coil, and local.means lor producing said untiined high 'reauency potential.

ln testimony whereof We our signaturcs.

JOSEPH O. li/lAUBORGNE. GUY HEL.

